Anogenital human papillomaviruses (HPVs) are the causative agents of the sexually transmitted disease, genital warts. A subset of these HPVs are also associated with genital cancers including cervical cancer in women and penile cancer in men. The HPV genotype 16 (HPV-16) is the HPV most frequently associated with cervical cancer. The research efforts in Dr. Lambert's laboratory are directed at characterizing the life cycle of papillomaviruses and understanding their contribution to human cancer. During the current grant period, Dr. Lambert's laboratory has 1) performed genetic and biochemical studies on E1 and E2 genes to learn further their roles in viral transcription and replication, 2) using a novel series of cervical epithelial cells harboring HPV-16 DNA, assessed the role of viral DNA integration in cervical cancer and discovered there to be a fundamental switch in viral DNA replication in the viral life cycle, and 3) using a comprehensive set of novel transgenic mouse lines expressing HPV-26 E6 and/or E7 in stratified squamous epithelium discovered that E6 and E7 can alter the growth and differentiation of squamous epithelia, E7 is sufficient to induce cancers and can act in the promotion phase of carcinogenesis, in E6 and E7 each can abrogate normal cellular responses to radiation in vivo. The goals of this proposal are to understand further the role of papillomaviral E1 and E2 proteins in the papillomavirus life cycle and to learn how the human papillomavirus type 16 oncogenes E6 and E7 contribute to cancer development and affect responsiveness of the cancers to conventional radiation treatment. The specific aims are: 1) to study the role of specific properties of the E2 proteins in viral transcription DNA replication in terminally differentiated cells, and 3) to define further the role of HPV-16 E6 and E7 in carcinogenesis. The specific aims represent logical extensions of Dr. Lambert's current research directions and make use of critical reagents generated by the Lambert laboratory during the current grant period. These studies should contribute to our further understanding of papillomaviral life cycle and the role of HPVs in anogenital cancers.